Half of patients undergoing orthopedic surgery are vitamin D deficient, a new study shows – potentially slowing recovery. Vitamin D helps heal bones and increase muscle strength, two processes vital for surgery recovery.

“In arthritis you have [damage to] the joint, but the muscles that drive the joint are extraordinarily affected by vitamin D levels. In order for the ‘motors’ for the joints to work you have to get vitamin D up,” explains Joseph Lane, MD, professor of orthopaedic surgery and chief of the Metabolic Bone Disease Service at Hospital for Special Surgery in New York City, who led the study.

Reversing vitamin D deficiency is important for all patients, especially those with arthritis. Dr. Lane believes people with arthritis will respond well to vitamin D, which will not only increase bone quality, but also help reduce the risk of bone fracture associated with rheumatoid arthritis. “This [vitamin plays] a very critical part of protecting the skeleton.”

For the study, published in The Journal of Bone and Joint Surgery, Lane and his research team measured vitamin D levels in 723 patients slated to have orthopaedic surgery between January 2007 and March 2008 at Hospital for Special Surgery.

Levels of vitamin D above 32 ng/mL were considered normal. Levels between 20 and 32 ng/mL were considered insufficient and levels below 20 ng/mL were categorized as deficient.

Based on those categories, 43 percent of all participants had insufficient levels and 40 percent had deficient levels.

When the analysis was broken down by area of surgery, trauma patients were most lacking in D: 66 percent had insufficient levels and 52 percent were deficient. When it came to hip and knee replacement patients, 38 percent had insufficient levels and 48 percent had deficient levels. Patients who were younger, male, African-American or Hispanic were most likely to suffer from a deficiency.

“What this is saying is a large number of people are coming in with low vitamin D or on the edge,” Dr. Lane explains. So he says whatever the issue that brings you to an orthopaedic doctor, checking vitamin D levels should be part of your pre-op program.

A person can absorb vitamin D through sunlight, but most people aren’t outside enough to get the recommended amount. Doctors say the easiest way to boost levels is with supplements. Dr. Lane says if your levels are low heading into surgery, you can start taking supplements even at that point and your levels will likely improve by the time bone is actually beginning to heal two to four weeks later.

“I don’t think it makes much difference in the first two to four weeks because bone is preparing to heal,” Dr. Lane says. “If you can recognize it you can pretty much correct it within two to four weeks and that’s the time you’ll need it.”

Dr. Lane says people should consult with their doctor, but he says 2,000-4,000 milligrams of vitamin D a day should correct levels for most people.

“That doesn’t mean you can make people heal by putting them on vitamin D,” Dr. Lane explains. “But in the absence of vitamin D there will be people who don’t heal following fractures. Assuming you do good surgery and don’t get infected, the overwhelming cause of failure to heal is low vitamin D.”

Mark Spangehl, MD, works in the department of orthopaedic surgery at the Mayo Clinic in Arizona and has doubts about this study.

“There is no evidence in that study that the vitamin D deficiency has actually had an impact, positive or negative, on recovery,” Dr. Spangehl says. “Any correlation to recovery, or damaging patient recovery, or having any influence at all on patient recovery is purely speculative.”

Dr. Spangehl says the study is useful for raising awareness and addressing the problem of vitamin D deficiency in the general population. But he says further study is needed to draw any conclusions beyond that.

“The next step would be to see if certain levels of deficiency actually have a correlation to a negative outcome in specific groups of surgical patients,” Dr. Spangehl says. “Vitamin D deficiency may certainly be a problem in the general population relating to osteoporosis with subsequent fragility fractures, but again there is nothing in this [study] that suggests that patient recovery after surgery is being damaged by the levels of vitamin D deficiency noted.”